Department of Physics and Astronomy, Supervisor: Ralph Pudritz
Evidence is growing for the hypothesis that life emerged through purely chemical means, however many questions still need to be answered. The first life molecules were likely RNA polymers due to their ability to store and replicate genetic information, and catalyze their own replication. My supervisor (Ralph Pudritz) and I are currently interested in how the building blocks of these first life molecules (i.e. the nucleotides) formed on the early Earth. One possibility is that nucleobases—the characteristic molecules in nucleotides—were synthesized within asteroids and comets, and delivered to the early Early by the fragments of these bodies. These nucleobases could then react with other molecules in the primordial soup to form the first nucleotides; which could link up and eventually form the first life molecules. The main evidence for an early-Earth delivery of nucleobases is in the meteoritic record (See Figure 1). Adenine, Guanine and Uracil have been measured in many types of carbonaceous meteorites, and are strongly thought to be extraterrestrial in origin (Callahan et al. 2011). To understand the formation of such molecules within the parent bodies of these meteorites, we run thermodynamic simulations of the reactions that have been demonstrated to form nucleobases in the lab.
Pearce & Pudritz 2015